Portable self-contained flashlight and switch device therefor



March 29, 1955 F. J. BERLINGER PORTABLE SELF-CONTAINED FLASHLIGHT AND WITCH DEVICE THEREFOR Filed March 21, 1951 IN V EN TOR. Frederzbkd Berlin United States Patent PORTABLE SELF-CONTAINED FLASHLIGHT AND SWITCH DEVICE THEREFOR Frederick J. Berlinger, Cincinnati, Ohio Application March 21, 1951, Serial No. 216,731

4 Claims. (Cl. 24010.6)

This invention relates to a portable, self-contained flashlight and has for its principal object the provision of a novel circuit closing actuator means for a flashlight which may be readily depressed and held in circuit closed position with the thumb of the hand that grasps the flashlight and which may also be rotated in its said depressed position to secure a mechanical locking action for the circuit closing means.

Another object of the invention is to provide a flashlight which will be particularly useful to physicians for making oral, and other related physical examinations; and specifically in adapting the flashlight of my prior Patent No. 2,312,305 of March 2, 1943 for use as a general purpose light for the diagnoses of external disorders of the human body.

With the foregoing and other objects in view I have devised the construction illustrated in the accompanying drawing forming a part of this specification.

In the drawing:

Fig. l is a perspective view of my flashlight illustrated as manually held in operative position.

Fig. 2 is a front elevational view of my flashlight. P Fig. 3 is an enlarged section taken on line 3-3 of Fig. 4 is a section on line 44 of Fig. 3.

In the specific embodiment of the invention shown in the drawings there is illustrated a metal casing 6 that has an open top 7 and a closed bottom 8. One or more dry cell batteries 9 in their usual cardboard sleeves are housed in the casing for limited axial movement; downward movement of the batteries being adapted to close a normally open switch 10 disposed between the bottom 8 of the casing and the batteries. As best illustrated in Fig. 3 the switch comprises a metal, expansile coil spring 11 in contact with the casing bottom and having its uppermost coil 12 encircling a reduced sleeve on an electrically non-conductive washer 13 that has its shouldered portion in contact with a bottom 14 of the battery 9. The opposite end of the spring 11 is developed into an upstanding contact 15 which engages the bottom of the battery cup contact when said battery is depressed within the casing to thereby close an electric lamp circuit for the flashlight, as will be fully set forth hereinafter.

A cap 16 is removably secured to the top 7 of the easing and preferably comprises a sleeve part 17 which encircles the upper end of the casing and has a tight, sliding fit with the casing wall. The cap preferably has an independently formed, tubular upper part 170 which is rigidly secured to the sleeve part by a suitable connection such as an annular groove 18 turned in the exterior wall of the tubular part into which the upper peripheral edge 19 of the sleeve is spun.

The cap is normally held in position on the casing by detent means such as a spring finger 20 mounted on the cap which snaps into a peripheral groove 21 formed in the exterior of the casing 6 adjacent its open end 7. The spring finger 20 is the upper free end of a pocket clip 22 for the flashlight, said clip being constructed from a spring metal strip bent to form a clip part 23 and having its intermediate portion 24 looped through spaced openings 2526 formed in the sleeve. The opposite free end of the strip is developed into the casing engaging finger 20 which extends through another opening 27 formed in said sleeve and into the peripheral groove 21 in the casing. The finger is placed under suflicient tension to hold the casing and cap in fixed positions for all normal uses of the flashlight, it being understood that Patented Mar. 29, 1955 when it is necessary to replace the batteries 9 the cap may be removed from the case by manually pulling the cap and case apart with sutiicient force to overcome the spring and slot connection.

A battery engaging switch actuator element 28 carrying a lamp holder 29 is freely mounted for selective reciprocable or rotatable movements on the cap 16, said movements being obtained exteriorly of the flashlight by manipulation of the element. In this respect it is also important to the operation of the element that its reciprocating movement provides a free sliding relationship between the cap and said element to actuate the switch 10 whilst rotation of said parts serves to frictionally lock said parts in switch closed positions. To the foregoing ends switch actuator element 28 comprises a bushing 30 formed with a relatively large cylindrical lower portion 31 and a smaller cylindrical upper portion 32 disposed in axial alignment and which form between them an annular shoulder 33. The bushing is reciprocably and rotatably mounted in a two-diameter through bore 34 formed through the axial center of the upper part 17 of the cap, the bore portions of different diameters being in axial alignment and forming between them a shoulder 35.

The bushing has a central bore 36 formed therethrough into which is fitted the lower end 37 of a hollow gooseneck tube 38 for the lamp holder 29. A socket piece 39 is fixed to the upper end of the gooseneck and has a recess 40 therein for receiving a lamp bulb 41, a sleeve contact 42 of said lamp being threaded in the recess by means of one or more detents 44 struck in the side wall 45 of the socket piece and which cooperate with the usual threads in the sleeve contact. A suitable friction cap 46 fitted over the end of the free end of the socket piece 39 may enclose and protect the lamp, if desired. A rod 47 of stiff, electrical conductive material extends through the center of the gooseneck 38 and is electrically insulated therefrom by a sleeve 48 made of electrically non-conductive material. The upper end of the rod 47 is in contact with the center terminal 49 of the lamp whilst the lower end of said rod is in electrical contact with the usual center terminal 50 of the battery 9.

With particular reference to Fig. 3 it will be noted that the spring 10 constantly thrusts the battery 9 upwardly in an axial direction thus constantly maintaining good electrical contacts between the battery terminals and the connection between the rod 47 and the center terminal 50 of the battery 9 and also normally forcing the shoulder 33 of the bushing 30 against the shoulder 35 in the cap 16. When it is desired to actuate the lamp 41 of the flashlight, the case is held in the hand with the thumb engaging the gooseneckiin the natural position indicated in Fig. 1 of the drawing. By depressing the gooseneck with the thumb the switch actuator element 28 is moved axially thus depressing batteries 9 in the casing until the upstanding contact 15 engages the bottom 14 of the battery thus completing an electrical circuit between the batteries and the lamp filament to actuate the latter. In this switch on position the completed electrical circuit consists of contact 15, battery casing 6, cap 16, bushing 30, gooseneck 38, socket piece 39, detent 44, lamp sleeve terminal 42, filament for lamp 41, center terminal 49, rod 47, and the upper, center terminal 50 for the batteries, and thence through the batteries to the lowermost bottom 14 of the batteries. Upon releasing the pressure of the thumb on the gooseneck the spring 10 will return the batteries 9 and switch ele ment 28 to their normal positions shown in Fig. 3, thus holding switch 10 open in which position the lamp will remain in unenergized, off condition.

The switch actuator element may be locked in either its on or its off position and to this end the tubular, upper part 17 of the cap is provided with a concentrically disposed, annular flange 51 which depends from the part and snugly engages the side wall of the lower cylindrical portion 31 of the bushing for the switch actuator element. As most clearly illustrated in Fig. 4 the flange has at least two spaced slits 5252 formed in its lower edge which form between them in the flange a free, leaf 53. This leaf 53 is bent slightly inwardly to provide a guide and friction spring element which cooperates with a guide way that takes the form of a flat 54 milled in the side wall of the lower portion 31 of bushing 30. The width of the flat is somewhat greater than the tangential distance between the slits 5252 so that the edges of the inwardly bent leaf 53 slidably engage the edge portions of the flat 54 to resist forces which tend to cause relative rotary movement between the cap 16 and the switch element 28 when the latter is manually depressed or moved axially by the spring 10. Itwill therefore be noted that the leaf 53 serves as an effective means to guide the switch actuator element during axial reciprocation thereof. When it is required to lock the switch actuator element in either its closed or opened position his only necessary to rotate the gooseneck 38 relative to the cap whilst the parts are manually held in either position, whereby the spring finger 53 engages the cylindrical side wall portion of the bushing thus forcing it outwardly and setting up an inward thrust of the finger against said wall whereby the switch actuator element will be locked against axial and rotary movements. The switch is released by rotating the switch actuator element in the cap until the tension on the leaf 53 of the cap is relieved by the clearance provided by the flat 54 whereupon the element may again be free for axially directed reciprocatory movement in the cap.

As has been hereinbefore pointed out the detent means on the cap 16 normally holds the cap on the flashlight casing by cooperation of the finger 20 with a peripheral groove 21 formed in the casing wall adjacent its open end. When desirable the spring connection of the detent means between the cap and casing may be overcome by manually forcing the cap and the casing together whereby the cap will be free to slide over the casing. This telescopic action of the cap and casing moves the battcries in an axial direction until the fixed contact engages the bottom 14 of the cup terminal of the lowermost battery thereby closing the circuit to the lamp 41. The flashlight parts will be held in this circuit closed position by the spring pressure of the finger against the casing wall, the switch being opened again only by pulling the cap and casing apart so that they assume the normal condition indicated in Fig. 3. In this connection it will be seen that the lamp holder 29 may at all times be swiveled to and locked in any desired position.

What is claimed is:

l. In a flashlight the combination of a tubular casing having a closed bottom and an opposed open end, a battery axially movable within the casing, a fixed battery engaging switch contact between the bottom of the casing and the battery, a cap fitted over the open end of the casing, a through-bore formed in the cap in axial alignment with the battery in the casing, an actuator bushing freely mounted for rectilinear movement in the through-bore, stop means between the cap and bushing for limiting the outward movement of the bushing in the cap to fix the normal open switch position of the bushing, an elongated, inflexible lamp holder secured at its lower end on the bushing and projecting beyond the cap, an electric lamp conductor within, and insulated from, the holder and having its lower end in electrical engagement with the central battery terminal, expansile spring means between the bottom of the casing and bottom of the battery for normally biasing the battery, bu'shing and'the lamp holder to open switch positions, and cooperative spring means between the cap and the bushing made operative by lamp holder controlled, rotary movement of the bushing for locking the bushing on the cap when the battery, bushing and lamp holder have been depressed against the action of the expansile spring to closed switch positions.

2. In a flashlight according to claim 1 characterized by the fact that the cooperative spring means consists of a flat portion formed on the cylindrical face of the actuator bushing, and a friction spring element mounted on the cap for rectilinear sliding engagement against the said flat portion and placed under locking pressure by engagement against the cylindrical face of the actuator upon rotation of said bushing relative to the cap.

3. In a flashlight according to claim 2 further characterized by the fact that the cap has an integral annular flange encircling the cylindrical bushing, and the friction spring element is an inwardly bent portion of that flange located between two spaced slits formed through the lower edge portion of the said flange.

4. In a flashlight the combination of a tubular casing having a closed bottom and an opposed open end, a battery axially movable within the casing, a fixed battery engaging switch contact between the bottom of the casing and the battery, a cap fitted over the open end of the casing, a two-diameter through-bore formed in the cap in axial alignment with the battery in the casing and-providing an inwardly facing shoulder therein, a two-diameter actuator bushing snugly seated in the through-bore in the cap for rectilinear movement therein, said bushing having an axial bore formed therethrough, and an outwardly facing shoulder in engagement with the shoulder in the cap to fix the normal open switch position of the bushing, a lamp holder comprising a gooseneck tube having its lower end extending through and secured in the axial bore in the bushing, a lamp socket secured to the free external end of the tube, a lamp in the socket, a conductor rod within the tube, means for electrically insulating the rod from the tube, the upper end of the rod being in electrical contact with the lamp, and the lower end projecting from the bushing and in electrical contact with the battery terminal, an expansile spring means between the bottom of the casing and the battery for normally biasing the battery, bushing and the lamp holder to open switch positions, and cooperative spring means between the cap and the bushing made operative by rotary movement of the lamp holder and for locking the bushing in the cap when the battery, bushing and lamp holder have been depressed against the action of the expansile spring to closed switch positions.

References Cited in the file of this patent UNITED STATES PATENTS 1,145,586 Herold July 6, 1915 1,232,824 Mayhew July 10, 1917 2,312,305 Berlinger Mar. 2, 1943 

